U.S. patent number 10,577,695 [Application Number 15/574,526] was granted by the patent office on 2020-03-03 for method for manufacturing discharge surface treatment electrode and method for manufacturing film body.
This patent grant is currently assigned to Mitsubishi Electric Corporation. The grantee listed for this patent is Mitsubishi Electric Corporation. Invention is credited to Hidetaka Katogi, Yoshikazu Nakano, Nobuyuki Sumi.
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United States Patent |
10,577,695 |
Katogi , et al. |
March 3, 2020 |
Method for manufacturing discharge surface treatment electrode and
method for manufacturing film body
Abstract
A method for manufacturing a discharge surface treatment
electrode includes: a first laying of laying powder particles to
form a first powder layer; and a first binding of binding some of
the powder particles in the first powder layer to each other. The
method further includes: a second laying of further laying the
powder particles on the first powder layer in which some of the
powder particles are bound to each other to form a second powder
layer; and a second binding of binding some of the powder particles
in the second powder layer to each other to form a stacked body of
granulated particles. A region having a different porosity from
another region is formed inside the stacked body.
Inventors: |
Katogi; Hidetaka (Tokyo,
JP), Sumi; Nobuyuki (Tokyo, JP), Nakano;
Yoshikazu (Tokyo, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Mitsubishi Electric Corporation |
Chiyoda-ku |
N/A |
JP |
|
|
Assignee: |
Mitsubishi Electric Corporation
(Chiyoda-ku, JP)
|
Family
ID: |
60265770 |
Appl.
No.: |
15/574,526 |
Filed: |
December 28, 2016 |
PCT
Filed: |
December 28, 2016 |
PCT No.: |
PCT/JP2016/089181 |
371(c)(1),(2),(4) Date: |
November 16, 2017 |
PCT
Pub. No.: |
WO2018/123050 |
PCT
Pub. Date: |
July 05, 2018 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20180291511 A1 |
Oct 11, 2018 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B22F
3/008 (20130101); B22F 3/1109 (20130101); B22F
1/0011 (20130101); C23C 24/087 (20130101); B33Y
10/00 (20141201); B22F 7/02 (20130101); C23C
24/103 (20130101); B05D 3/0254 (20130101); B22F
2304/10 (20130101); B05D 7/536 (20130101); B05D
5/12 (20130101); B05D 7/50 (20130101); B33Y
80/00 (20141201); B05D 3/02 (20130101); B05D
1/12 (20130101) |
Current International
Class: |
B05D
5/12 (20060101); B33Y 10/00 (20150101); B22F
1/00 (20060101); C23C 24/10 (20060101); B22F
3/11 (20060101); B22F 3/00 (20060101); C23C
24/08 (20060101); B22F 7/02 (20060101); B05D
3/02 (20060101); B05D 7/00 (20060101); B05D
1/12 (20060101); B33Y 80/00 (20150101) |
Field of
Search: |
;427/58,189,202 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
693 872 |
|
Mar 2004 |
|
CH |
|
2003-301202 |
|
Oct 2003 |
|
JP |
|
2005-213557 |
|
Aug 2005 |
|
JP |
|
2006-322034 |
|
Nov 2006 |
|
JP |
|
4684973 |
|
May 2011 |
|
JP |
|
2013-159818 |
|
Aug 2013 |
|
JP |
|
2013-159828 |
|
Aug 2013 |
|
JP |
|
2015-060703 |
|
Sep 2013 |
|
JP |
|
2015-140461 |
|
Aug 2015 |
|
JP |
|
WO 2007/133258 |
|
Nov 2007 |
|
WO |
|
Other References
International Search Report and Written Opinion dated Apr. 4, 2017
in PCT/JP2016/089181 filed Dec. 28, 2016. cited by applicant .
Office Action dated Jul. 10, 2018 in German patent Application No.
11 2016 002 010.4, (with English Translation), 12 pages. cited by
applicant.
|
Primary Examiner: Talbot; Brian K
Attorney, Agent or Firm: Oblon, McClelland, Maier &
Neustadt, L.L.P.
Claims
The invention claimed is:
1. A method for manufacturing a discharge surface treatment
electrode, the method comprising: a first laying of laying powder
particles so as to form a first powder layer; a first binding of
binding some of the powder particles in the first powder layer to
each other; a second laying of further laying the powder particles
on the first powder layer in which some of the powder particles are
bound to each other so as to form a second powder layer, wherein
the powder particles in the first powder layer and the powder
particles in the second powder layer include a same type of
granulated powder particles having a particle size distribution of
a first value; and a second binding of binding some of the powder
particles in the second powder layer to each other so as to form a
stacked body of the powder particles, wherein a region having a
different porosity from another region is formed inside the stacked
body based on different positions of application of a binder toward
the powder particles in the first binding and the second
binding.
2. The method for manufacturing the discharge surface treatment
electrode according to claim 1, wherein the first binding and the
second binding in the application of the binder include selectively
injecting a binder toward the powder particles to be bound.
3. The method for manufacturing the discharge surface treatment
electrode according to claim 2, further comprising inputting the
stacked body into a furnace and sintering or calcining the powder
particles.
4. The method for manufacturing the discharge surface treatment
electrode according to claim 1, wherein the first binding and the
second binding include selectively heating the powder particles to
be bound.
5. The method for manufacturing the discharge surface treatment
electrode according to claim 4, wherein the powder particles are
calcined or sintered by the heating.
6. The method for manufacturing the discharge surface treatment
electrode according to claim 4, wherein the powder particle is a
granulated powder particle in which metal powder particles and a
binder are mixed, and the binder is melted by the heating and then
the melted binder is solidified.
7. The method for manufacturing the discharge surface treatment
electrode according to claim 1, wherein the first powder layer is
laid on a base, and the first powder layer and the base are bound
to each other in the first binding.
8. The method for manufacturing the discharge surface treatment
electrode according to claim 1, wherein the first powder layer is
laid on a base, and a region that is in contact with the base in
the first powder layer is a non-bound region that is not bound to
the base or a low bound region in which a binding force to the base
is lower than a binding force between the powder particles in
another region.
9. The method for manufacturing the discharge surface treatment
electrode according to claim 1, wherein the stacked body has
regions with different porosities in a direction in which the
powder particles are stacked.
10. The method for manufacturing the discharge surface treatment
electrode according to claim 1, wherein the stacked body has
regions with different porosities in a direction perpendicular to a
direction in which the powder particles are stacked.
11. A method for manufacturing a film body, the method comprising:
causing the discharge surface treatment electrode manufactured by
the method for manufacturing the discharge surface treatment
electrode according to claim 1 to face a workpiece; and forming a
film on the workpiece by applying a voltage to the discharge
surface treatment electrode and generating a discharge phenomenon
between the discharge surface treatment electrode and the
workpiece.
12. The method for manufacturing the discharge surface treatment
electrode according to claim 1, wherein a first porosity of the
powder particles in the first powder layer is less than a second
porosity of the powder particles in the second powder layer.
Description
FIELD
The present invention relates to a method for manufacturing a
discharge surface treatment electrode used for a discharge surface
treatment and a method for manufacturing a film body.
BACKGROUND
There is a discharge surface treatment technique in which a film is
formed on a surface of a workpiece using a discharge surface
treatment electrode. In Patent Literature 1, a green compact
obtained by compacting a powder inside a mold, a sintered compact
obtained by sintering a green compact, or a calcined compact
obtained by calcining a green compact is used for a discharge
surface treatment electrode. In a discharge surface treatment
technique using a discharge surface treatment electrode, the
discharge surface treatment electrode is caused to face a workpiece
and a discharge phenomenon is generated between the discharge
surface treatment electrode and the workpiece. A powder collapses
from the discharge surface treatment electrode and floats due to
the discharge explosive force of the discharge phenomenon. Then,
the floating powder is melted and solidified on the surface of the
workpiece, and a film is thereby formed on the surface of the
workpiece.
In the discharge surface treatment electrode, it is necessary for a
powder to collapse due to the discharge explosive force. Thus, in
the discharge surface treatment electrode, it is necessary to
provide a certain distance between powder particles forming the
discharge surface treatment electrode, i.e., to control the
porosity of the discharge surface treatment electrode.
CITATION LIST
Patent Literature
Patent Literature 1: Japanese Patent Application Laid-open No.
2006-322034
SUMMARY
Technical Problem
However, in order to control the porosity by the above conventional
technique, there is a problem in that it takes time to set a
solidification condition and it is difficult to stabilize a
quality. As the solidification condition, the magnitude of the
pressure for compacting a powder inside a mold and time for
applying the pressure are exemplified.
Furthermore, it is in some cases necessary to change the shape of a
discharge surface treatment electrode according to the treatment
condition of the discharge surface treatment, i.e., the material of
a workpiece used for the discharge surface treatment and the film
quality of a film formed on the surface of the workpiece. In this
case, it is necessary to manufacture a mold according to the shape
of a discharge surface treatment electrode or to form a desired
shape by post-processing a discharge surface treatment electrode
manufactured using a common mold. Therefore, cost of manufacturing
a discharge surface treatment electrode is increased due to the
cost of manufacturing a mold according to the shape or cost of
performing post-processing. Examples of the post-processing
performed on a discharge surface treatment electrode include
discharge processing.
The present invention has been achieved in view of the above, and
an object of the present invention is to obtain a method for
manufacturing a discharge surface treatment electrode that can
control the porosity with a stable quality while suppressing
manufacturing cost.
Solution to Problem
In order to solve the above problems and to achieve the object, the
present invention includes: a first laying step of laying powder
particles so as to form a first powder layer; and a first binding
step of binding some of the powder particles in the first powder
layer to each other. The present invention further includes: a
second laying step of further laying the powder particles on a
powder layer in which some of the powder particles are bound to
each other so as to form a second powder layer; and a second
binding step of binding some of the powder particles in the second
powder layer to each other so as to form a stacked body of the
powder particles. A region having a different porosity from another
region is formed inside the stacked body.
Advantageous Effects of Invention
The present invention exhibits an effect in that a discharge
surface treatment electrode that has a high degree of freedom in
shape and that can freely set the porosity can be obtained without
using a mold.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross-sectional view of a granulated powder particle
used for a discharge surface treatment electrode according to a
first embodiment of the present invention.
FIG. 2 is a flowchart illustrating a method for manufacturing the
discharge surface treatment electrode according to the first
embodiment.
FIG. 3 is a diagram illustrating steps of manufacturing the
discharge surface treatment electrode according to the first
embodiment.
FIG. 4 is a diagram illustrating an example of the discharge
surface treatment electrode according to the first embodiment and
an example of a discharge surface treatment using the discharge
surface treatment electrode.
FIG. 5 is a diagram illustrating another example of the discharge
surface treatment electrode according to the first embodiment and
another example of the discharge surface treatment using the
discharge surface treatment electrode.
FIG. 6 is a diagram illustrating still another example of the
discharge surface treatment electrode according to the first
embodiment.
FIG. 7 is a diagram illustrating a discharge surface treatment
electrode according to a first modification of the first
embodiment.
FIG. 8 is a diagram illustrating a discharge surface treatment
electrode according to a second modification of the first
embodiment.
FIG. 9 is a flowchart illustrating a method for manufacturing a
discharge surface treatment electrode according to a second
embodiment of the present invention.
FIG. 10 is a diagram illustrating steps of manufacturing the
discharge surface treatment electrode according to the second
embodiment.
FIG. 11 is a diagram illustrating a method for manufacturing a
discharge surface treatment electrode according to a third
embodiment of the present invention.
FIG. 12 is a diagram illustrating a discharge surface treatment
electrode according to a fourth embodiment of the present
invention.
FIG. 13 is a cross-sectional view illustrating a granulated powder
particle used for manufacturing the discharge surface treatment
electrode according to the fourth embodiment.
DESCRIPTION OF EMBODIMENT
Hereinafter, embodiments of a method for manufacturing a discharge
surface treatment electrode and a method for manufacturing a film
body according to the present invention will be described in detail
based on the drawings. The present invention is not limited by
these embodiments.
First Embodiment
FIG. 1 is a cross-sectional view of a granulated powder particle
used for a discharge surface treatment electrode according to a
first embodiment of the present invention. As illustrated in FIG.
1, a granulated powder particle 21 is a powder obtained by
collecting and binding a plurality of metal powder particles 21m
with a first binder 21b. In the following description, collecting
and binding a plurality of metal powder particles with a binder is
referred to as granulation.
In a discharge surface treatment using the discharge surface
treatment electrode, the metal powder particles 21m are caused to
float between the discharge surface treatment electrode and a
workpiece. Thus, it is necessary to make the particle diameter of
the metal powder particles 21m sufficiently smaller than the gap
between the discharge surface treatment electrode and the
workpiece. Specifically, the particle diameter is desirably 1 .mu.m
to 10 .mu.m. By binding the metal powder particles 21m to each
other with the first binder 21b, the granulated powder particle 21
having a particle diameter of 150 .mu.m or more is obtained.
In a step of manufacturing the discharge surface treatment
electrode according to the first embodiment, when prepared metal
powder particles have a particle diameter of 1 .mu.m to 10 .mu.m,
the metal powder particles are bound to each other with the first
binder 21b, and when prepared metal powder particles have a
particle diameter of larger than 10 .mu.m, the metal powder
particles are subjected to pulverization or the like to obtain
metal powder particles having a particle diameter of 1 .mu.m to 10
.mu.m and then the metal powder particles are bound to each other
with the first binder 21b to obtain the granulated powder particle
21 having a particle diameter of 150 .mu.m. The particle diameter
referred to herein is indicated by a value called D50. D50 is a
value determined from a particle size distribution of the whole
powder. Specifically, when a powder is divided into two, i.e.,
particles having a larger particle diameter than a certain particle
diameter and particles having a smaller particle diameter than the
certain particle diameter, the particle diameter at which the
particles having a larger particle diameter than the certain
particle diameter become equal to the particles having a smaller
particle diameter than the certain particle diameter is indicated
as a D50 value. Metal powder particles having a particle diameter
of larger than 10 .mu.m may be used for manufacturing the discharge
surface treatment electrode without pulverizing and granulating the
metal powder particles. For example, there is a case where metal
powder particles having a particle diameter of 50 .mu.m can be used
for manufacturing the discharge surface treatment electrode without
granulating the metal powder particles. That is, a powder used for
manufacturing the discharge surface treatment electrode also
includes metal powder particles that are not granulated.
Examples of a metal used for the metal powder particles 21m include
titanium (Ti), silicon (Si), chromium (Cr), iron (Fe), cobalt (Co),
nickel (Ni), zirconium (Zr), molybdenum (Mo), barium (Ba), rhenium
(Re), tungsten (W), titanium carbide (TiC), cobalt chromium (CoCr),
tungsten carbide (WC), titanium silicon carbide (TiSiC), and
molybdenum sulfide (MoS).
The first binder 21b contains a solute and a solvent. As the solute
of the first binder 21b, paraffin is exemplified. As the solvent of
the first binder 21b, an alcohol-based or ketone-based nonpolar
solvent that is a nonaqueous medium liquid is exemplified. The
content of paraffin in the first binder 21b is desirably at least
0.1% by weight and no more than 2.0% by weight.
The metal powder particle 21m having a particle diameter of 1 .mu.m
to 10 .mu.m needs to be handled carefully when being handled as
they are, but by binding the metal powder particles 21m to each
other with the first binder 21b to form the granulated powder
particle 21 of 150 .mu.m or more, it becomes easy to handle the
metal powder particles 21m.
FIG. 2 is a flowchart illustrating a method for manufacturing a
discharge surface treatment electrode 1 according to the first
embodiment. FIG. 3 is a diagram illustrating steps of manufacturing
the discharge surface treatment electrode 1 according to the first
embodiment. In the drawings of the present application, granulated
powder particles to which a second binder described below has been
supplied are indicated by double circles, granulated powder
particles that are bound by the second binder or sintered or
calcined metal powder particles are indicated by hatched circles,
and granulated powder particles to which the second binder is not
supplied are indicated by hollow circles.
First, in process p1 illustrated in FIG. 3, a first laying step of
laying the granulated powder particles 21 on a table 10 is
performed (step S1). In the first laying step, a first powder layer
11 is formed on the table 10. Here, the table 10 is used as a base
on which the granulated powder particles 21, which are a powder,
are laid. Subsequently, in process p2 illustrated in FIG. 3, a
binder injection device 3 selectively injects a second binder 4
toward some of the granulated powder particles 21 forming the first
powder layer 11 (step S2). As a result, the second binder 4 is
supplied to some of the granulated powder particles 21. Here, it is
satisfactory if the binder injection device 3 is an injection
device that can control the injection position of the second binder
4. For example, an injection device used for a powder additive
manufacturing apparatus also called a 3D printer can be used.
Furthermore, as the second binder 4, a material that is in a liquid
state at the time of injection and that is solidified after being
dried is used. The same material as that of the first binder 21b
used for the granulated powder particle 21 is desirably used for
the second binder 4. The second binder 4 is preferably injected
from the binder injection device 3 by spray atomization by which
the second binder 4 is less likely to contain coarse paraffin. If
coarse paraffin is not contained in the injected second binder 4,
paraffin is less likely to remain as a foreign matter when the
second binder 4 is heated and dried.
In addition, the second binder 4 is desirably injected in an inert
gas atmosphere or a vacuum environment. Examples of the inert gas
include nitrogen, argon, and helium. However, these descriptions do
not exclude that the second binder 4 is injected in the
atmosphere.
Subsequently, in process p3 illustrated in FIG. 3, the first powder
layer 11 is heated by a heating device 5 to dry the second binder 4
(step S3). As a result, the granulated powder particles 21 are
bound to each other at a place where the second binder 4 has been
supplied in the first powder layer 11. A first binding step of
binding the granulated powder particles 21 to which the second
binder 4 has been supplied in the first powder layer 11 to each
other is performed by injecting the second binder 4 in step S3 and
drying the second binder 4 in step S4.
The type of a heat source used for the heating device 5 is not
particularly limited. The granulated powder particle 21 has a
specific resistance much higher than the metal powder particle 21m.
Thus, in the heating in step S3, in place of an electric heat
source exemplified by an electron beam, a non-electric heat source
exemplified by a heater or a light source exemplified by a laser
may be used as a heat source used for the heating device 5.
Subsequently, in process p4 illustrated in FIG. 3, a second laying
step of further laying the granulated powder particles 21 on the
first powder layer 11 is performed (step S4). In the second laying
step, a second powder layer 12 is formed on the first powder layer
11.
Subsequently, in process p5 illustrated in FIG. 3, the binder
injection device 3 selectively injects the second binder 4 toward
some of the granulated powder particles 21 forming the second
powder layer 12 (step S5). As a result, the second binder 4 is
supplied to some of the granulated powder particles 21. As
illustrated in process p5 of FIG. 3, the area to which the second
binder 4 is supplied is smaller than that in the first powder layer
11. That is, in the second powder layer 12, the number of the
granulated powder particles 21 bound to each other is smaller than
that in the first powder layer 11.
Subsequently, in process p6 illustrated in FIG. 3, the second
powder layer is heated by the heating device 5 to dry the second
binder 4 (step S6). As a result, the granulated powder particles 21
are bound to each other at a place where the second binder 4 has
been supplied in the second powder layer 12. A second binding step
of binding the granulated powder particles 21 to which the second
binder 4 has been supplied in the second powder layer 12 to each
other is performed by supplying the second binder 4 in step S5 and
drying the second binder 4 in step S6. In the second binding step,
the granulated powder particles 21 to which the second binder 4 has
been supplied in the second powder layer 12 are also bound to the
first powder layer 11. As a result, a stacked body 2 in which a
plurality of the granulated powder particles 21 are bound to each
other is obtained. Thereafter, by repeating the second laying step
and the second binding step, the stacked body 2 having a desired
thickness is obtained.
Subsequently, in process p7 illustrated in FIG. 3, the stacked body
2 is moved from the table 10, and the granulated powder particles
21 that are not bound are removed (step S7). In order to facilitate
removal of the stacked body 2 from the table 10, the second binder
4 is injected into the first powder layer 11 such that the second
binder 4 does not reach the granulated powder particles 21 that are
in contact with the table 10. As a result, the region formed by the
granulated powder particles 21 that are in contact with the table
10 becomes a non-bound region that is not bound to the table 10;
therefore, removal of the stacked body 2 is facilitated. It is
possible to supply, to the granulated powder particles 21 that are
in contact with the table 10, the second binder 4, the amount of
which is smaller than the amount of the second binder 4 supplied to
the granulated powder particles 21 stacked on the upper layer. In
this case, the binding force of the granulated powder particles 21
that are in contact with the table 10 to the table 10 is lower than
the binding force between the granulated powder particles 21 in the
upper layer. As a result, the region formed by the granulated
powder particles 21 that are in contact with the table 10 becomes a
low bound region in which the binding force to the table 10 is
reduced, and removal of the stacked body 2 can be facilitated.
Subsequently, an inputting step of inputting the stacked body 2
from which the granulated powder particles 21 that are not bound
has been removed into a high-temperature furnace, subliming the
first binder 21b, and sintering or calcining the metal powder
particles 21m is performed to obtain the discharge surface
treatment electrode 1 (step S8).
In the discharge surface treatment electrode 1 manufactured by the
manufacturing method described above, by controlling the position
to which the second binder 4 is supplied, the ratio of the
granulated powder particles 21 that are bound in the first powder
layer 11 can be different from that in the second powder layer 12.
To put it in other words, the ratio of the granulated powder
particles 21 that are not bound in the first powder layer 11 can be
different from that in the second powder layer 12, i.e., the
porosity of the region formed by using the first powder layer 11
can be different from that of the region formed by using the second
powder layer 12.
In the example illustrated in FIG. 3, the ratio of the granulated
powder particles 21 bound to each other in the second powder layer
12 is lower than the ratio of the granulated powder particles 21
bound to each other in the first powder layer 11. That is, the
porosity of the second powder layer 12 is higher than that of the
first powder layer 11. In this manner, in the method for
manufacturing the discharge surface treatment electrode 1 according
to the first embodiment, a region with a different porosity from
the other regions can be formed inside the discharge surface
treatment electrode 1. In addition, by reducing the porosity of the
first powder layer 11 stacked in the earlier stage, stacking can be
stabilized at the initial stage of formation of the stacked body 2.
The porosity of the first powder layer 11 may be increased and the
porosity of the second powder layer 12 may be reduced.
Furthermore, the granulated powder particles 21 at a desired
position can be bound to each other. Thus, by changing the position
to which the second binder 4 is supplied, the discharge surface
treatment electrode 1 can be manufactured in various shapes.
Therefore, it is unnecessary to manufacture molds according to
discharge surface treatment electrodes having different shapes
unlike the case of manufacturing a discharge surface treatment
electrode by forming a green compact. In addition, it is
unnecessary to form a discharge surface treatment electrode into a
desired shape by performing post-processing. Thus, the cost of
manufacturing a mold according to a shape or cost of performing
post-processing can be reduced. This enables manufacturing cost of
the discharge surface treatment electrode to be suppressed. These
descriptions do not exclude shaping the discharge surface treatment
electrode 1 according to the first embodiment by post-processing
the discharge surface treatment electrode 1.
When a material that is solid at room temperature and has a melting
point of 100.degree. C. or lower is used for the second binder 4,
the second binder 4 that has been injected into the granulated
powder particle 21 is naturally solidified in a temperature
environment lower than or equal to the melting point, and the
granulated powder particles 21 can be bound to each other. Thus, in
the case where the material that is solid at room temperature and
has a melting point of 100.degree. C. or lower is used for the
second binder 4, even if the heating steps in steps S3 and S6 are
omitted, the granulated powder particles 21 can still be bound to
each other.
The material of the metal powder particles 21m contained in the
granulated powder particles 21 used in the first powder layer 11
may be different from that used in the second powder layer 12. It
is of course possible to, in a case of repeating the second laying
step and the second binding step, use a different material for the
metal powder particles 21m contained in the granulated powder
particles 21 in each of the stacked power layers.
In addition, because the granulated powder particles 21 themselves
include the first binder 21b, the injection of the second binder 4
in steps S2 and S5 may be omitted and some of the granulated powder
particles 21 laid may be heated to melt the first binder 21b
contained in the granulated powder particles 21. In this case, the
melted first binder 21b is cooled and solidified again, and the
granulated powder particles 21 are thereby bound to each other.
It is possible to omit inputting the stacked body 2 into a
high-temperature furnace in step S8 depending on the conditions
required for a film formed on a workpiece by a discharge surface
treatment using the discharge surface treatment electrode 1.
Omission of inputting the stacked body into a high-temperature
furnace causes the first binder 21b and the second binder 4 not to
be sublimed and causes paraffin to remain in the discharge surface
treatment electrode 1. In a case where a discharge surface
treatment is performed using the discharge surface treatment
electrode 1 in which paraffin remains, paraffin may be mixed in a
film formed on a workpiece. That is, if there is no problem in
mixing paraffin in a film formed on a workpiece, it is possible to
omit inputting the stacked body 2 into a high-temperature furnace
in step S8.
Furthermore, it is difficult to bind the metal powder particles 21m
having a particle diameter suitable for a discharge surface
treatment, i.e., having a particle diameter of 1 .mu.m to 10 .mu.m,
to each other with the second binder 4 at a desired position due to
an influence of wettability. For this reason, the coarse granulated
powder particle 21 is used for a powder laid in steps S1 and S4.
However, under a condition under which an influence of wettability
can be ignored, not the granulated powder particles 21 but metal
powder particles that are not granulated may be directly laid as a
powder used for the discharge surface treatment electrode. Examples
of the condition under which an influence of wettability can be
ignored include a case where even with the discharge surface
treatment electrode 1 manufactured using metal powder particles
having a particle diameter less affected by wettability, a film can
be formed on a workpiece by a discharge surface treatment. For
example, there is a case where the discharge surface treatment
electrode 1 can be manufactured by directly laying metal powder
particles having a particle diameter of 50 .mu.m.
Next, a discharge surface treatment using the discharge surface
treatment electrode 1 having regions with different porosities will
be described. FIG. 4 is a diagram illustrating an example of the
discharge surface treatment electrode according to the first
embodiment and an example of a discharge surface treatment using
the discharge surface treatment electrode 1. The discharge surface
treatment electrode 1 illustrated in FIG. 4 is bonded to a jig 50
for attaching the discharge surface treatment electrode 1 to a
discharge surface treatment device (not illustrated). In addition,
the discharge surface treatment electrode 1 is disposed so as to
face a workpiece 150. The jig 50 is an energizing unit for
generating a discharge phenomenon between the discharge surface
treatment electrode 1 and the workpiece 150, and is made of a
conductive material. Examples of the conductive material used for
the jig 50 include a metal, an alloy, and conductive ceramics.
In the discharge surface treatment electrode 1, a plurality of
regions, i.e., a first region 20, a second region 30, and a third
region 40, are stacked in this order from the side of the jig 50
toward the workpiece 150. In the discharge surface treatment
electrode 1, the region closer to the jig 50 has a smaller
porosity. That is, the second region 30 has a smaller porosity than
the third region 40, and the first region 20 has a smaller porosity
than the second region 30.
By applying a voltage to the jig 50 in process p11, a voltage is
also applied to the discharge surface treatment electrode 1, and a
discharge phenomenon is generated between the discharge surface
treatment electrode 1 and the workpiece 150. As a result of the
generation of the discharge phenomenon, a powder collapses in the
third region 40, which is the outermost layer, and a first film 140
is formed on the workpiece 150 as illustrated in process p12.
Subsequently, as illustrated in process p13, a powder collapses in
the second region 30 and then in the first region 20, and a second
film 130 and a third film 120 are formed on the workpiece 150. As a
result, a film body having a film formed on the workpiece 150 is
obtained.
In the discharge surface treatment electrode 1 illustrated in FIG.
4, the starting points of discharge generation are dispersed due to
the high porosity in the third region 40, which is the outermost
layer, and therefore a discharge phenomenon is easily started when
a voltage is applied to the discharge surface treatment electrode
1.
In addition, a film formed from a region with a high porosity has a
low film density, and a film formed from a region with a low
porosity has a high film density. That is, by controlling the
porosity in the discharge surface treatment electrode 1, the film
density of a film formed on the workpiece 150 can be controlled.
Here, the first film 140 indicated in process p13 in FIG. 4 is
formed mainly from the third region 40 of the discharge surface
treatment electrode 1, the second film 130 is formed mainly from
the second region 30 of the discharge surface treatment electrode
1, and the third film 120 is formed mainly from the first region 20
of the discharge surface treatment electrode 1. Thus, the second
film 130 has a higher film density than the first film 140, and the
third film 120 has a higher film density than the second film
130.
Furthermore, by making the materials of the metal powder particles
21m used for the first region 20, the second region 30, and the
third region 40 different from one another, the materials forming
the first film 140, the second film 130, and the third film 120
formed on the workpiece 150 can be made different from one another.
That is, by controlling the porosity and the material of the metal
powder particles 21m for each region in the discharge surface
treatment electrode 1, the film quality of a film formed on the
workpiece 150 can be easily controlled.
Furthermore, while a region with a low porosity, such as the first
region 20, collapses to form a film, it is possible to create an
environment in which a large number of the metal powder particles
21m are present between the discharge surface treatment electrode 1
and the workpiece 150, and therefore a discharge surface treatment
efficiency can be improved.
Next, a description will be given of another example of the
discharge surface treatment using the discharge surface treatment
electrode 1 in which the porosity is made different for each
region. FIG. 5 is a diagram illustrating another example of the
discharge surface treatment electrode 1 according to the first
embodiment and another example of the discharge surface treatment
using the discharge surface treatment electrode 1. The discharge
surface treatment electrode 1 illustrated in FIG. 5 bonded to the
jig 50. In addition, the discharge surface treatment electrode 1 is
disposed so as to face the workpiece 150.
The discharge surface treatment electrode 1 illustrated in FIG. 5
has regions with different porosities in a direction perpendicular
to a direction in which the granulated powder particles 21 are
stacked in the step of manufacturing the discharge surface
treatment electrode 1. Specifically, the discharge surface
treatment electrode 1 has the first region 20 with a low porosity
in a region on the left side of the paper surface and the second
region 30 with a high porosity in a region on the right side of the
paper surface.
A film formed by applying a voltage to the jig 50 in process p21
illustrated in FIG. 5 and generating a discharge phenomenon in
process p22 has regions with different film qualities in the plane
direction of the workpiece 150. Specifically, a first film 220 on
the left side of the paper surface formed mainly from the first
region 20 has a higher film density and a larger thickness than a
second film 230 on the right side of the paper surface formed
mainly from the second region 30.
In this way, by using the discharge surface treatment electrode 1
having regions with different porosities in a direction
perpendicular to the direction in which the granulated powder
particles 21 are stacked, the film quality of a film can be varied
in the plane direction of the workpiece 150. Furthermore, the
discharge surface treatment electrode 1 having regions with
different porosities in a direction perpendicular to the direction
in which the granulated powder particles 21 are stacked can be also
easily manufactured by controlling the position of the granulated
powder particles 21 to be bound to each other by the manufacturing
method illustrated in FIGS. 2 and 3. The discharge surface
treatment electrode 1 is only required to have a region with a
porosity different from the other regions. For example, in both of
the direction in which the granulated powder particles are stacked
and a direction perpendicular to the direction in which the
granulated powder particles are stacked, the discharge surface
treatment electrode 1 may have regions with different
porosities.
Next, a description will be given of still another example of the
discharge surface treatment electrode 1 in which the porosity is
made different for each region. FIG. 6 is a diagram illustrating
still another example of the discharge surface treatment electrode
1 according to the first embodiment. The discharge surface
treatment electrode 1 illustrated in FIG. 6 is bonded to the jig 50
for attaching the discharge surface treatment electrode 1 to a
discharge surface treatment device (not illustrated).
The discharge surface treatment electrode 1 illustrated in FIG. 6
has a shape having a recess portion on the surface thereof. Each of
the first region 20, the second region 30, and the third region 40
having different porosities from one another is also formed into a
shape having a recess portion 23 on the surface side thereof. Each
of the second region 30 and the third region 40, which are not in
direct contact with the jig 50, has a V shape as a whole. The
discharge surface treatment electrode 1 in which the regions each
having an even porosity are each shifted in the direction in which
the granulated powder particles 21 are stacked can also be easily
manufactured by controlling the position of the granulated powder
particles 21 to be bound.
Next, a description will be given of the discharge surface
treatment electrode 1 according to a first modification of the
first embodiment. FIG. 7 is a diagram illustrating discharge
surface treatment electrode 1 according the first modification of
the first embodiment. In the discharge surface treatment electrode
1 according to the first modification, the discharge surface
treatment electrode 1 is bound to the jig 50 in the step of
manufacturing the discharge surface treatment electrode 1.
Specifically, in the manufacturing step illustrated in FIG. 3, the
granulated powder particles 21 are laid on the jig 50 in place of
the table 10 to directly form the first powder layer 11 on the jig
50. In this manner, in the first modification, the jig 50 is used
as a base on which the granulated powder particles 21 as a powder
are laid. Furthermore, in process p2 illustrated in FIG. 3, by
allowing the second binder 4 to reach the granulated powder
particles 21 that are in contact with the jig 50 in the first
powder layer 11, the granulated powder particles 21 are bound to
the jig 50.
As described above, the discharge surface treatment electrode 1
illustrated in FIG. 7 is bound in advance to the jig 50 for
attaching the discharge surface treatment electrode 1 to a
discharge surface treatment device. Here, the discharge surface
treatment electrode 1 is formed with a certain degree of porosity,
and therefore has a characteristic of being brittle. Thus, in a
case where the discharge surface treatment electrode 1 is directly
held in order to bond the discharge surface treatment electrode 1
to the jig 50, the discharge surface treatment electrode 1 may be
broken by the holding force. In contrast, according to the first
modification, the discharge surface treatment electrode 1 is formed
such that it is bound to the jig 50; therefore, the discharge
surface treatment electrode 1 can be handled by holding the jig 50.
Thus, in the discharge surface treatment electrode 1 according to
the first modification, the discharge surface treatment electrode 1
can be prevented from being broken due to the holding. Furthermore,
the larger discharge surface treatment electrode 1 is more brittle;
therefore, the larger discharge surface treatment electrode 1 is
difficult to handle. However, according to the first modification,
the discharge surface treatment electrode 1 is formed while being
supported by the jig 50 in advance, and this makes handling easy.
Therefore, the size of the discharge surface treatment electrode 1
can be increased.
Next, a description will be given of the discharge surface
treatment electrode 1 according to a second modification of the
first embodiment. FIG. 8 is a diagram illustrating the discharge
surface treatment electrode 1 according to the second modification
of the first embodiment. In the discharge surface treatment
electrode 1 according to the second modification, the discharge
surface treatment electrode 1 is bound to a support portion 51
disposed on the jig 50 in the step of manufacturing the discharge
surface treatment electrode 1.
Specifically, in the manufacturing step illustrated in FIG. 3, the
granulated powder particles 21 are laid on the support portion 51
in place of the table 10 to directly form the first powder layer 11
on the support portion 51. In this manner, in the second
modification, the support portion 51 is used as a base on which the
granulated powder particles 21 as a powder are laid. Furthermore,
in process p2 illustrated in FIG. 3, by also allowing the second
binder 4 to reach the granulated powder particles 21 that are in
contact with the support portion 51 in the first powder layer 11,
the granulated powder particles 21 are bound to the support portion
51.
Similarly to the discharge surface treatment electrode 1
illustrated in the first modification, the support portion 51 may
be formed directly on the jig 50 by repeating a powder laying step
and a powder binding step on the jig 50. Alternatively, the support
portion 51 may be formed by other methods such as a metal spraying
method and a sputtering method. In addition, the separately
prepared support portion 51 may be bonded to the jig 50 to form the
support portion 51 on the jig 50.
Alternatively, after the support portion 51 formed on the jig 50,
the discharge surface treatment electrode 1 may be formed on the
support portion 51, or after the discharge surface treatment
electrode 1 is formed on the support portion 51, the support
portion 51 may be bonded to the jig 50.
In this way, by disposing the support portion 51 between the jig 50
and the discharge surface treatment electrode 1, in a case where
the material of the jig 50 is incompatible with the material of the
metal powder particles 21m used for the discharge surface treatment
electrode 1, the support portion 51 is formed of a material
compatible with both of the materials of the jig 50 and the metal
powder particles 21m and thus compatibility between the jig 50 and
the metal powder particle 21m can be obtained. Examples of
incompatibility between different materials include galvanic
corrosion occurring between titanium and an aluminum alloy.
In addition, by disposing the support portion 51 at a portion of
the discharge surface treatment electrode 1 that is unnecessary in
an actual discharge surface treatment, the powder material used for
manufacturing the discharge surface treatment electrode 1 can be
reduced and manufacturing cost can be suppressed. Furthermore, as
illustrated in FIG. 8, the support portion 51 is provided with a
protruding portion 51a; therefore, the shape of the discharge
surface treatment electrode 1 can be closer to a shape of only a
portion necessary for a discharge surface treatment. Therefore, the
powder material used for manufacturing the discharge surface
treatment electrode 1 can be further reduced.
Furthermore, according to the second modification, similarly to the
case where the discharge surface treatment electrode 1 is formed on
the jig 50, the discharge surface treatment electrode 1 can be
handled by holding the support portion 51 or the jig 50. Therefore,
the discharge surface treatment electrode 1 can be prevented from
being broken due to the discharge surface treatment electrode 1
being held. In addition, the size of the discharge surface
treatment electrode 1 can be increased.
Second Embodiment
FIG. 9 is a flowchart illustrating a method for manufacturing a
discharge surface treatment electrode 1Q according to a second
embodiment of the present invention. FIG. 10 is a diagram
illustrating steps of manufacturing the discharge surface treatment
electrode 1Q according to the second embodiment. The same reference
numerals are given to the same components as those of the above
first embodiment, and a detailed description thereof will be
omitted. In a method for manufacturing the discharge surface
treatment electrode 1Q according to the second embodiment, some of
the granulated powder particles 21 are selectively sintered or
calcined without using a second binder, and the granulated powder
particles 21 are bound thereby to each other. Hereinafter, the
method for manufacturing the discharge surface treatment electrode
1Q according to the second embodiment will be described in
detail.
First, in process p31 illustrated in FIG. 10, a first laying step
of laying the granulated powder particles 21 on the table 10 is
performed (step S11). In the first laying step, the first powder
layer 11 is formed on the table 10. Here, the table 10 is used as a
base on which the granulated powder particles 21, which are a
powder, are laid. Subsequently, in process p32 illustrated in FIG.
10, part of the first powder layer 11 is selectively heated by the
heating device 5 (step S12).
In step S12, the selectively heated granulate powder particles 21
are heated to a sintering temperature or a calcining temperature,
and the metal powder particles 21m contained in the selectively
heated granulated powder particles 21 are thereby sintered or
calcined and are bound to each other. That is, in step S12, a first
binding step of binding the metal powder particles 21m contained in
the selectively heated granulated powder particles 21 to each other
is performed.
In the second embodiment, in step S12, the metal powder particles
21m are sintered or calcined, and therefore the first binder 21b
contained in the granulated powder particles is sublimed at this
point of time. Thus, in step S12, fumes and gas generated by
sublimation of the first binder 21b are desirably recovered by a
recovery device.
In addition, the type of a heat source used for the heating device
5 is not particularly limited. However, the heat source needs to be
a heat source that can raise the temperature to a sintering
temperature or a calcining temperature by selectively inputting
energy into part of a powder layer. Examples of such a heat source
include a heat source that emits an electron beam or a laser.
However, the energy supplied from a heat source is not required to
have strength sufficient to raise the temperature to such a level
that the metal powder particle 21m is melted, and is only required
to have such strength as to raise the temperature to a temperature
at which the metal powder particle 21m is sintered or calcined. In
a case where the heat source used for the heating device 5 is a
heat source that emits a laser, it is satisfactory if tens to
hundreds of watts of energy is obtained. In a case where the heat
source used for the heating device 5 is a heat source that emits an
electron beam, it is satisfactory if 1,000 to 3,000 watts enough to
calcine the metal powder particles 21m is obtained.
In step S12, the granulated powder particles 21 are desirably
heated in an inert gas atmosphere or a vacuum environment. Examples
of the inert gas include nitrogen, argon, and helium. The
granulated powder particles 21 are desirably heated by irradiation
with an electron beam in a vacuum environment from a viewpoint of
preventing oxidation of the metal powder particles 21m at the time
of sintering or calcining. However, these descriptions do not
exclude heating the granulated powder particles 21 in the
atmosphere and heating the granulated powder particles 21 using
other heat sources.
Subsequently, in process p33 illustrated in FIG. 10, a second
laying step of further laying the granulated powder particles 21 on
the first powder layer 11 is performed (step S13). In the second
laying step, the second powder layer 12 is formed on the first
powder layer 11.
Subsequently, in process p34 illustrated in FIG. 10, part of the
second powder layer 12 is selectively heated by the heating device
5 (step S14). In step S14, the selectively heated granulated powder
particles 21 are heated to a sintering temperature or a calcining
temperature, and the metal powder particles 21 in contained in the
selectively heated granulated powder particles 21 are thereby
sintered or calcined and are bound to each other. That is, in step
S14, a second binding step of binding the metal powder particles
21m contained in the selectively heated granulated powder particles
21 to each other is performed. In addition, the first binder 21b
contained in the granulated powder particles 21 is sublimed at this
point of time. Furthermore, as illustrated in FIG. 10, in process
p34, the area of the heated granulated powder particles is smaller
than that in the first powder layer 11.
In the second binding step, the metal powder particles 21m
contained in the heated granulated powder particles 21 in the
second powder layer 12 are also bound to the first powder layer 11.
As a result, a stacked body 222 in which a plurality of the metal
powder particles 21m are bound to each other is obtained.
Thereafter, by repeating the second laying step and the second
binding step, the stacked body 222 having a desired thickness is
obtained.
Subsequently, in process p35 illustrated in FIG. 10, the stacked
body 222 is moved from the table 10 to remove the unheated
granulated powder particles 21 (step S15). In order to facilitate
removal of the stacked body 222 from the table 10, when the first
powder layer 11 is heated, the granulated powder particles 21 that
are in contact with the table 10 are not heated. As a result, the
region formed by the metal powder particles 21m contained in the
granulated powder particles 21 that are in contact with the table
10 becomes a non-bound region that is not bound to the table 10;
therefore, removal of the stacked body 222 is facilitated. Energy
input into the granulated powder particles 21 that are in contact
with the table 10 may be kept lower than the energy input into the
granulated powder particles 21 stacked on the upper layer. In this
case, the binding force of the metal powder particles 21m contained
in the granulated powder particles 21 that are in contact with the
table 10 to the table 10 is lower than the binding force between
the metal powder particles 21m contained in the granulated powder
particles 21 in the upper layer. As a result, the region formed by
the granulated powder particles 21 that are in contact with the
table 10 becomes a low bound region in which the binding force to
the table 10 is reduced, and removal the stacked body 222 can be
facilitated.
In the second embodiment, in steps S12 and S14 i.e., in the first
binding step and the second binding step, the first binder 21b is
sublimed and the metal powder particles 21m are sintered or
calcined. Thus, the stacked body 222 can be used as it is as the
discharge surface treatment electrode IQ in which no paraffin
remains. Thus, an inputting step of inputting the stacked body 222
into a high-temperature furnace is unnecessary unlike the first
embodiment. As a result, manufacturing equipment for manufacturing
the discharge surface treatment electrode 1 and a manufacturing
step can be simplified.
In the discharge surface treatment electrode 1Q manufactured by the
manufacturing method described above, by controlling the position
of the granulated powder particles 21 to be heated, the ratio of
the metal powder particles 21m that are bound in the first powder
layer 11 can be different from that in the second powder layer 12.
To put it in other words, the porosity of the region formed by
using the first powder layer 11 can be different from that of the
region formed by using the second powder layer 12 in the discharge
surface treatment electrode 1Q.
In the example illustrated in FIG. 10, the ratio of the granulated
powder particles 21 heated in the second powder layer 12 is lower
than the ratio of the granulated powder particles 21 heated in the
first powder layer 11. That is, the porosity of the second powder
layer 12 is higher than that of the first powder layer 11. In this
manner, in the method for manufacturing the discharge surface
treatment electrode 1Q according to the second embodiment, a region
with a different porosity from the other regions can be formed
inside the discharge surface treatment electrode IQ. In addition,
by reducing the porosity of the first powder layer 11 stacked in
the earlier stage, stacking can be stabilized at the initial stage
of formation of the stacked body 222. The porosity of the first
powder layer 11 may be increased and the porosity of the second
powder layer 12 may be reduced.
Furthermore, the metal powder particles 21m contained in the
granulated powder particles 21 at a desired position can be bound
to each other. Thus, by changing the position to be heated, the
discharge surface treatment electrode 1Q can be manufactured in
various shapes. Therefore, it is unnecessary to manufacture molds
according to discharge surface treatment electrodes having
different shapes unlike the case of manufacturing a discharge
surface treatment electrode by forming a green compact. In
addition, it is unnecessary to form a discharge surface treatment
electrode into a desired shape by performing post-processing. Thus,
the cost of manufacturing a mold according to a shape or cost of
performing post-processing can be reduced. This enables
manufacturing cost of the discharge surface treatment electrode to
be suppressed. These descriptions do not exclude shaping the
discharge surface treatment electrode 1Q according to the second
embodiment by post-processing the discharge surface treatment
electrode 1Q.
The material of the metal powder particles contained in the
granulated powder particles 21 used in the first powder layer 11
may be different from that used in the second powder layer 12. It
is of course possible to, in a case of repeating the second laying
step and the second binding step, use a different material for the
metal powder particles 21m contained in the granulated powder
particles 21 in each of the stacked power layers.
Furthermore, in steps S11 and S13, not the granulated powder
particles 21 but the metal powder particles 21m may be directly
laid. Even in this case, the metal powder particles 21m can be
bound to each other by sintering or calcining the metal powder
particles 21m at a desired position by selectively heating the
metal powder particles 21m by the heating device 5. When the metal
powder particles 21m are directly laid, the first binder 21b is not
sublimed at the time of heating. Thus, a recovery device for
recovering fumes and gas generated by sublimation of the first
binder 21b is unnecessary.
It is of course possible to manufacture the discharge surface
treatment electrode 1Q having a porosity controlled as illustrated
in FIGS. 4, 5, and 6 of the first embodiment by the method for
manufacturing the discharge surface treatment electrode 1Q
according to the second embodiment and perform a discharge surface
treatment by using the discharge surface treatment electrode 1Q.
Also in this case, a similar effect to that described in the first
embodiment can be obtained.
Furthermore, as illustrated in FIGS. 7 and 8 of the first
embodiment, the discharge surface treatment electrode 1Q may be
formed on the jig 50 or the support portion 51 by the method for
manufacturing the discharge surface treatment electrode 1Q
according to the second embodiment. Also in this case, a similar
effect to that described in the first embodiment can be
obtained.
Third Embodiment
FIG. 11 is a diagram illustrating a method for manufacturing a
discharge surface treatment electrode 1R according to a third
embodiment of the present invention. The same reference numerals
are given to the same components as those of the above embodiments,
and a detailed description thereof will be omitted. In processes
p41 to p45 illustrated in FIG. 11, the granulated powder particles
21 are supplied onto the table 10 or the first powder layer 11 in a
desired pattern shape. Then, the granulated powder particles 21
formed in a desired pattern shape are heated by the heating device
5, and the granulated powder particles 21 are bound to each other
or the metal powder particles 21m are bound to each other by
solidifying the first binder 21b contained in the granulated powder
particles 21 after remelting or by sintering or calcining the metal
powder particles 21m contained in the granulated powder particles
21. A second binder may be injected toward the granulated powder
particles to bind the granulated powder particles to each other. As
a result, the discharge surface treatment electrode 1R is obtained.
In the third embodiment, by changing the shape of a desired
pattern, the discharge surface treatment electrode 1R having a
region with porosity different from the other regions can be
obtained. In the example illustrated in FIG. 11, a region formed by
the second powder layer 12 has a higher porosity than a region
formed by the first powder layer 11.
Fourth Embodiment
FIG. 12 is a diagram illustrating a discharge surface treatment
electrode 1S according to a fourth embodiment of the present
invention. In the fourth embodiment, a particle diameter d.sub.1 of
the granulated powder particles 21 used in the first powder layer
11 is different from a particle diameter d.sub.2 of granulated
powder particles 31 used in the second powder layer 12.
Specifically, the particle diameter d.sub.2 of the granulated
powder particles 31 is larger than the particle diameter d.sub.1 of
the granulated powder particles 21. A region formed by the second
powder layer 12 in which the granulated powder particles 31 having
a larger particle diameter are laid can have a higher porosity than
a region formed by the first powder layer 11.
Although detailed illustration is omitted, the granulated powder
particle 31 is also formed by collecting and binding a plurality of
metal powder particles to each other with a first binder. Also in
the fourth embodiment, the first powder layer 11 is formed, the
granulated powder particles 21 are bound to each other in the first
powder layer 11, the second powder layer 12 is formed on the first
powder layer 11, and the granulated powder particles 31 are bound
to each other in the second powder layer 12. As described in the
above other embodiments, the binding of the granulated powder
particles 21 in the first powder layer 11 and the binding of the
granulated powder particles 31 in the second powder layer 12 may be
achieved by supplying the second binder 4, by solidifying the first
binder contained in the granulated powder particles after
remelting, or by performing sintering or calcining due to supply of
energy from a heat source.
FIG. 13 is a cross-sectional view illustrating a granulated powder
particle 22 used for manufacturing the discharge surface treatment
electrode 1S according to the fourth embodiment. In the granulated
powder particle 22 illustrated in FIG. 13, a binder film 41 is
formed around the granulated powder particle 21. The particle
diameter of the granulated powder particle 22 can be changed by
changing the film thickness of the binder film 41. In this manner,
the discharge surface treatment electrode illustrated in FIG. 12
may be manufactured using the granulated powder particles 22 having
different particle diameters by changing the film thickness of the
binder film 41. In particular, the larger the film thickness of the
binder film 41 is, the larger the distance between the laid
granulated powder particles 21 is. Therefore, the porosity of the
discharge surface treatment electrode 1S can be controlled by
changing the thickness of the binder film 41.
Note that the configurations described in the foregoing embodiments
are examples of the present invention; combining with other
publicly known techniques is possible, and partial omissions and
modifications are possible without departing from the spirit of the
present invention.
REFERENCE SIGNS LIST
1, 1Q, 1R, 1S discharge surface treatment electrode; 2, 222 stacked
body; 3 binder injection device; 4 second binder; 5 heating device;
10 table; 11 first powder layer; 12 second powder layer; 20 first
region; 23 recess portion; 30 second region; 40 third region; 50
jig; 51 support portion; 51a protruding portion; 21, 22, 31
granulated powder particle; 21b first binder; 21m metal powder
particle; 120 third film; 130 second film; 140 first film; 150
workpiece; 220 first film; 230 second film.
* * * * *